Heat-treating apparatus



Mmh 22, 1938. B R @H 2,111,919

HEAT TREATING APPARATUS Y Filed Des. 10. 1937 Patented Mar. 22, 1938 UNITED STATES PATET OFFICE 4 Claims.

-My invention h2is for its object to provide a means for produ'cing a'predetermined maximum pneumatic pressure on ihe surface of a liquid in a container that communicates With a receptacle to raise the level 01 liquid to aydesired level in the receptacle.

The invention also prqvides a liquid-weighted, pneumatic-pressure, release v.a1ve for limiting the difierential-head of liquids in a receptacle communicating with a closed container and expelled pneumatically from the container inco the receptacle.

The invention particularly provides a pneumatic press ure means for expellin-g a ferrous metal heao-treatingliquid from a closed reservoir 130 a heat-treating trough to produce a de sired differential hea?il between the liquicls in the reservoir and the trough, the reservoir having a movable, normally float-balanced valve member additionally weighted by a column of said liquid having the same cross sectional area as the valve seat anti a height the same as the desired differential head to limit ihe level of the liquid to Whi@h it may be raised in the trough by the pneumatic pressure in the reservoir.

The invention may be contained in structures of difierent forms and to illustrate a practical application of the invention, I have selected a heat-treating apparatus for heat-treating ferrous metals as an example of the various struc- 'tures contained in the invention and shall describe the selected structure hereinafter. The particular structure selected is shown in the accompanying drawing.

35 Fig. 1 illustrates a vertical section of the beattreating apparatus. Fig. 2 illustrates a top view.

Fig. 3 illustrates a section of the liquid-weighted release valve.

The apparatus is provided Wlth a substantially closed reservoir I that communicates with a trough 2 through an opening 4 formed in the lower end of the partitioning wall 5 that divides the reservoir from the trough. The trough 2 is providedwith means Tor supporting articles formed of a material that is physically modified by contact of liquids. As an example of the application of the invention, steel tools, such as punches I, that require liquid submersion to predetermined depths for short periods of time for tempering or hardening end 01 edgeportions, are secured by means of suitable clamping devices that may be readily operate'd 110 secure the punches in position for simultaneous heat-treatment of a plurality of the tools. Thus the punches I may be secured by pneumatic cylinders 8 that clamp the shanks orheads of the punches against an anvil er bridge IG. The pistons of the pneumatic cylinders 8 are provided Withclamping heads II that engage the shanks of the tools to position the tools so that thei r ends project to definite points with reference 130 the normal level of the liquid in the reservoir and the trough. v

The level of the liquid in the reservoir I is depressed pneumatically by int.roducing air under pressure into the reservoir. In the form of construction shown, a blower I2 is supported on the top cf the reservoir and is connected to the interior 0f the reservoir by means of the pipe I4. The blower is driven by a suitable motor for causing rotation of iosv fan to produce a pressure sufiicient to force the liquid above the level of the top of the opening 4 fromm the reservoir I into t-he trough 2.

The reservoir has a normally floatable valve thai; may be weighted by the liquid used. in the heat-treatment 015 the punches l 130 limit the rise cf the level of the liquid in the trough 2. The valve has a movable valve member E5 that seats upon a seat I! formed in 01 secured to the top wall of the reservoir I. The movable valve member has a shell I8, preferably cylindrical in form, having an internal diameter substantially the same as the immer diameter of the seat I'I. The shell has an opening 20 th-at may be closed by a plug 2I for filling the shell I8 to the desired depth and a plug 23 that may be loosened or removed. t0 lower the level -of the liquid in the chamber to the desired point, as may be determined by a suitable gauge 22. The weight of the liquid introduced into the chamber counteracts the pneumatic pressure produced by the blower to cause I;he riss of the level of the liquid in the trough. The valve is opened when the pressure rises to a predetermined point and allows the escape of the air introduced into the reservoir by the blower and thus maintains ehe level of the liquid constant. The quantiiy of the liquid introduced into the chamber is sufiicient 130 produce the desired differential head in the trough to submerge the lower ends of the punches I to the desired depth, The liquid that is used in heat-treating the articles aifords a convenient material for producing, with exactness, a; desired differential head in the liquid of the troughand reservoir. Introduction of ehe liquid into the shell I8 produces a differential head the same as the depth of the liquid in the Shell,

The movable valve member I5 is connected 130 a rod 24 that is slidably supported on the end of an arm or bracket secured to the upper end of the trough 2, and by a boss 21 formed in a bridge located in the valve seai: I1, the boss 21 having an opening through which the rod 24 may slidably move. The lower end of the rod is provided with a floai; 28 which substantially counterbalances the weight of the movable valve member I5 when the liquid contained in the shell I8 is removed. Ihe inner diameter of the valve seat, being substantially the same as the inne1 diameter of the shell, is pressed by a pressure corresponding to that produced by the blower I2 which lowers the level of the water in the reservoir when the valve is held closed by the weight of the column of liquid Within the shell I8, but when the pressure produced by the blower on the surface of the liquid in the reservoir I reaches a point sufi'icient to produce a difierential head. between the liquids in the reservoir and the trough substantially equal to the height of ehe column of the liquid in the shell, the pressure on the valve member is sufiiciently great to open the valve and allow the air to escape from the reservoir i as it is introduced into the reservoir by the blower I2, and thus the valve maintains the level of the liquid in the trough 2 at the desired point with reference to submergence of the lower ends of the tools. When it is desired to return the liquid from the trough to the reservoir, the circuii; cf the motor that drives the blower I2 may be opened to cause cessation of the operation of the blower, whereupon the air Will be forced from the reservoir through the pipe I4 and through the fan of the blower I2.

I claim:

1. In a hea.t-treating apparatus, a closed reservoir und. a trough for containing a heat-treating liquid, the trough having means for supporting the articles to be heattreated, a pneumatic pressure means connected to tl1e reservoir for forcing the liquid from the reservoir into Ehe trough, and a valve for opening the reservoir 130 allow the air to escape from the reservoir when the level of the liquid in the trough is ralsed to a desired predetermined level With respect 110 the articles to be heat-treated anal maintain the level of the liquid in the trough at the said predetermined level.

2. In a heat-treating apparatus, a closed reservoir and a. trough for containing a heat-treating liquid, the trough having means for supporting the articles to be heat-treated, a pneumatic pressure means connected to the reservoir for forcing the liquid from the reservoir into the trough, and the movable valve member of the valve having a, chamber for containing a liquid for weighting the valve to produce the desired diiferential head in the reservoir and the trough and operative to open the reservoir when the level in the trough is raised to a desired precletermined level With respect to the articles to be heat-treatecl.

3. In a heat-treaoing apparatus, a closed reservoir and a trough for containing a heat-treating liquid, the trough having means for supporting the articles to be heat-treated, a pneumatic pressure means connected to the reservoir for forcing ehe liquid from the reservoir lnto the trough, a float located in the liquid and counected to the movable valve member of the valve for normally fioating the valve member, and bhe movable valve member having a chamber for containing a liquid for counterpressing the pneumatic pressure in the reservoir and allowing the air to escape from the reservoir when the level of the liquid in the trough is raised to a pzedetermined poini; with respect to the articles beattreated.

4. In a heat-treating apparatus, a closed reservoir and a trough for containing a heat-treating liquid, the trough having means for supporting the articles to be heat-treatecl, a pneumatic pressure means connected 110 the reservoir for forcing the liquid from the reservoir into the trough, a valve having a movable valve mernber and a fixed valve seat for opening the reservoir, the valve member having a cylindrical chamber, the inner diameter of the chamber being substantially the same as the smaller diameter of the valve seat and for containing liquid, and a float for counterbalancing the weight of the valve member and cooperative With the pressure 015 the air upon the movable valva member to open the reservoir when the differential head produced is substantially equal 130 the height of the column of liquid in the movable valve member 130 allow the air 130 escape from the reservoir as it is introduced and maintain the level 0f the liquid in the trough at a predetermined point.

BERTIS H. URSCHEL. 

